IPAC2013 - List of Keywords (electromagnetic-fields)

Paper	Title	Other Keywords	Page
MOPWO007	Numerical Calculation of Electromagnetic Fields in Acceleration Cavities Under Precise Consideration of Coupler Structures	dipole, cavity, impedance, resonance	897
	C. Liu, W. Ackermann, W.F.O. Müller, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: Work supported by BMBF under contract 05H12RD5 The acceleration with superconducting radio frequency cavities requires dedicated couplers to transfer energy from the radio frequency source to the beam. Simultaneously, higher order mode couplers are installed to effectively suppress parasitic modes. Therefore, the numerical eigenmode analysis based on real-valued variables is no longer suitable to describe the dissipative acceleration structure. At the Computational Electromagnetics Laboratory (TEMF) a robust parallel eigenmode solver to calculate the eigenmodes in the lossy acceleration structure is available. This eigenmode solver is based on complex-valued finite element analysis and utilizes basis functions up to the second order on curved tetrahedral elements to enable the high precision elliptical cavity simulations. The eigenmode solver has been applied to the TESLA 1.3 GHz accelerating cavity to determine the resonance frequency, the quality factor and the corresponding field distribution for all 192 eigenmodes up to the 5th dipole passband (3.12 GHz).

MOPWO061	Numerical Approaches for Simulation of Stochastic Cooling in 2D Phase Space	emittance, simulation, coupling, storage-ring	1028
	M. Dolinska NASU/INR, Kiev, Ukraine C. Dimopoulou, A. Dolinskyy, F. Nolden GSI, Darmstadt, Germany
	A consolidated fluid-dynamics algorithm for the analysis of beam dynamics under the influence of the electromagnetic field is presented. Aiming at simulating stochastic cooling of particle beams in 2D space, two numerical algorithms solving the 2D Fokker-Planck Equation are described. As an alternative approach, a numerical method based on the macro-particle tracking turn in turn in the ring (i.e. in the time domain) is introduced. Some results of the simulation of the stochastic cooling in the Collector Ring by both methods are discussed.

TUPFI058	Simulation of Beam-induced Gas Plasma in High Gradient RF Field for Muon Colliders	electron, ion, simulation, plasma	1478
	K. Yonehara, M. Chung, A.V. Tollestrup Fermilab, Batavia, USA B.T. Freemire IIT, Chicago, Illinois, USA R.P. Johnson, T.J. Roberts Muons. Inc., USA R.D. Ryne LBNL, Berkeley, California, USA V. Samulyak BNL, Upton, Long Island, New York, USA K. Yu SBU, Stony Brook, USA
	There is a strong limit of available RF gradient in a vacuum RF cavity under magnetic fields because the magnetic field enhances a dark current density due to electron focusing and increases probability of an electric breakdown. This limits the cooling performance. A dense hydrogen gas filled RF cavity can break this limit because the gas acts as a buffer of dark current. However, RF power loading due to a beam-induced plasma in a dense gas filled RF cavity (plasma loading effect) is crucial to design the practical cavity. Experiment shows that the plasma loading can be mitigated in denser hydrogen gas and by doping a small amount of electronegative gas in the cavity. A complicate plasma chemical reaction should be dominated in such a dense hydrogen gas condition. A beam-induced plasma is simulated by taking into account the plasma chemistry to reproduce the condition by using the supercomputer at LBNL. We will also investigate the space charge effect in a dense gas in this effort.

WEPWO014	Rf Field-Attenuation Formulae for the Multilayer Coating Model	cavity, vacuum, coupling	2343
	T. Kubo, T. Saeki KEK, Ibaraki, Japan Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan
	Formulae that describe the RF electromagnetic field attenuation in the multilayer coating model with a single superconductor layer and a single insulator layer deposited on a bulk superconductor are derived with a rigorous calculation based on the Maxwell equations and the London equation.

WEPWO040	Design of HWR at RISP	cavity, simulation, quadrupole, niobium	2387
	G.-T. Park, H.J. Cha, H.C. Jung IBS, Daejeon, Republic of Korea
	At RISP, superconducting cavity resonators to accelerate the various ions in high current are being developed. In particular, hal-wave resonator (HWR) will be used for β=0.12, f=162.5 MHz. Here we present the structural analysis of HWR, which includes the prediction of resonant frequency shift during the manufacturing and testing process, stiffening measures to minimize the shift, and the tuning mechanism. The processes of welding, polishing, vacuuming, cooling (to crygenic temperature)as well as Lorentz force, helium pressure fluctuation, microphonics, and interaction with the helium vessel and tuning system will be simulated optimizing the frequency shift.

WEPEA037	Testing of Symplectic Integrator of Spin-orbit Motion Based on Matrix Formalism	simulation, storage-ring, lattice	2582
	A.N. Ivanov, S.N. Andrianov, N.V. Kulabukhova St. Petersburg State University, St. Petersburg, Russia R. Maier, Y. Senichev, D. Zyuzin FZJ, Jülich, Germany
	Investigation of spin-orbital motion in electromagnetic fields requires different numerical methods. Approaches for long-term evolution modelling need both performance and symplecticity. In this paper we discuss matrix maps method for numerical simulation. We examine symplectification and accuracy in terms of electostatic storage ring. The results are compared with traditional symplectic step-by-step methods.

THPWA032	Fields of Charged Particle Bunches in Chiral Isotropic Medium	radiation, polarization, vacuum, factory	3696
	S.N. Galyamin, A.A. Peshkov, A.V. Tyukhtin Saint-Petersburg State University, Russia
	Funding: Work is supported by Russian Foundation for Basic Research and the Dmitry Zimin "Dynasty" Foundation. We study electromagnetic fields produced by charged particle bunches moving in a chiral isotropic medium. Such properties are typical for most of organic matters and some artificial materials (metamaterials). Therefore, this subject is of interest for chemical, biological, and medical applications as well as for study of metamaterials. First, we investigate in detail the field of a point charge. We obtain exact and approximate formulas and develop algorithm for calculation of the point charge field. Further, we use these expressions for calculation of fields produced by finite size bunches. We also present the typical energetic patterns of radiation and spectra of energy losses. Possibilities of using the obtained results for different applications are discussed.

Paper

Title

Other Keywords

Page

Numerical Calculation of Electromagnetic Fields in Acceleration Cavities Under Precise Consideration of Coupler Structures

dipole, cavity, impedance, resonance

897

C. Liu, W. Ackermann, W.F.O. Müller, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: Work supported by BMBF under contract 05H12RD5
The acceleration with superconducting radio frequency cavities requires dedicated couplers to transfer energy from the radio frequency source to the beam. Simultaneously, higher order mode couplers are installed to effectively suppress parasitic modes. Therefore, the numerical eigenmode analysis based on real-valued variables is no longer suitable to describe the dissipative acceleration structure. At the Computational Electromagnetics Laboratory (TEMF) a robust parallel eigenmode solver to calculate the eigenmodes in the lossy acceleration structure is available. This eigenmode solver is based on complex-valued finite element analysis and utilizes basis functions up to the second order on curved tetrahedral elements to enable the high precision elliptical cavity simulations. The eigenmode solver has been applied to the TESLA 1.3 GHz accelerating cavity to determine the resonance frequency, the quality factor and the corresponding field distribution for all 192 eigenmodes up to the 5th dipole passband (3.12 GHz).

MOPWO061

Numerical Approaches for Simulation of Stochastic Cooling in 2D Phase Space

emittance, simulation, coupling, storage-ring

1028

M. Dolinska
NASU/INR, Kiev, Ukraine
C. Dimopoulou, A. Dolinskyy, F. Nolden
GSI, Darmstadt, Germany

A consolidated fluid-dynamics algorithm for the analysis of beam dynamics under the influence of the electromagnetic field is presented. Aiming at simulating stochastic cooling of particle beams in 2D space, two numerical algorithms solving the 2D Fokker-Planck Equation are described. As an alternative approach, a numerical method based on the macro-particle tracking turn in turn in the ring (i.e. in the time domain) is introduced. Some results of the simulation of the stochastic cooling in the Collector Ring by both methods are discussed.

TUPFI058

Simulation of Beam-induced Gas Plasma in High Gradient RF Field for Muon Colliders

electron, ion, simulation, plasma

1478

K. Yonehara, M. Chung, A.V. Tollestrup
Fermilab, Batavia, USA
B.T. Freemire
IIT, Chicago, Illinois, USA
R.P. Johnson, T.J. Roberts
Muons. Inc., USA
R.D. Ryne
LBNL, Berkeley, California, USA
V. Samulyak
BNL, Upton, Long Island, New York, USA
K. Yu
SBU, Stony Brook, USA

There is a strong limit of available RF gradient in a vacuum RF cavity under magnetic fields because the magnetic field enhances a dark current density due to electron focusing and increases probability of an electric breakdown. This limits the cooling performance. A dense hydrogen gas filled RF cavity can break this limit because the gas acts as a buffer of dark current. However, RF power loading due to a beam-induced plasma in a dense gas filled RF cavity (plasma loading effect) is crucial to design the practical cavity. Experiment shows that the plasma loading can be mitigated in denser hydrogen gas and by doping a small amount of electronegative gas in the cavity. A complicate plasma chemical reaction should be dominated in such a dense hydrogen gas condition. A beam-induced plasma is simulated by taking into account the plasma chemistry to reproduce the condition by using the supercomputer at LBNL. We will also investigate the space charge effect in a dense gas in this effort.

WEPWO014

Rf Field-Attenuation Formulae for the Multilayer Coating Model

cavity, vacuum, coupling

2343

T. Kubo, T. Saeki
KEK, Ibaraki, Japan
Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan

Formulae that describe the RF electromagnetic field attenuation in the multilayer coating model with a single superconductor layer and a single insulator layer deposited on a bulk superconductor are derived with a rigorous calculation based on the Maxwell equations and the London equation.

WEPWO040

Design of HWR at RISP

cavity, simulation, quadrupole, niobium

2387

G.-T. Park, H.J. Cha, H.C. Jung
IBS, Daejeon, Republic of Korea

At RISP, superconducting cavity resonators to accelerate the various ions in high current are being developed. In particular, hal-wave resonator (HWR) will be used for β=0.12, f=162.5 MHz. Here we present the structural analysis of HWR, which includes the prediction of resonant frequency shift during the manufacturing and testing process, stiffening measures to minimize the shift, and the tuning mechanism. The processes of welding, polishing, vacuuming, cooling (to crygenic temperature)as well as Lorentz force, helium pressure fluctuation, microphonics, and interaction with the helium vessel and tuning system will be simulated optimizing the frequency shift.

WEPEA037

Testing of Symplectic Integrator of Spin-orbit Motion Based on Matrix Formalism

simulation, storage-ring, lattice

2582

A.N. Ivanov, S.N. Andrianov, N.V. Kulabukhova
St. Petersburg State University, St. Petersburg, Russia
R. Maier, Y. Senichev, D. Zyuzin
FZJ, Jülich, Germany

Investigation of spin-orbital motion in electromagnetic fields requires different numerical methods. Approaches for long-term evolution modelling need both performance and symplecticity. In this paper we discuss matrix maps method for numerical simulation. We examine symplectification and accuracy in terms of electostatic storage ring. The results are compared with traditional symplectic step-by-step methods.

THPWA032

Fields of Charged Particle Bunches in Chiral Isotropic Medium

radiation, polarization, vacuum, factory

3696

S.N. Galyamin, A.A. Peshkov, A.V. Tyukhtin
Saint-Petersburg State University, Russia

Funding: Work is supported by Russian Foundation for Basic Research and the Dmitry Zimin "Dynasty" Foundation.
We study electromagnetic fields produced by charged particle bunches moving in a chiral isotropic medium. Such properties are typical for most of organic matters and some artificial materials (metamaterials). Therefore, this subject is of interest for chemical, biological, and medical applications as well as for study of metamaterials. First, we investigate in detail the field of a point charge. We obtain exact and approximate formulas and develop algorithm for calculation of the point charge field. Further, we use these expressions for calculation of fields produced by finite size bunches. We also present the typical energetic patterns of radiation and spectra of energy losses. Possibilities of using the obtained results for different applications are discussed.